I'v enever used FreeDNS, but I've used No-IP and DynDNS before perfectly fine. Best to set your router to update the dynamic IP automatically too, if it supports it, otherwise No-IP has a Windows GUI client that works well tool

I didn't host a webserver. It was just for FTP, RDP and Centralized IRC access. What do you define as a reasonable price? The free services offered by those sites worked fine for me. obviously you have to choose from one of their subdomains though (i.e - sswilson.dyndns.org)

"Real" domains cost $10 a year. I'm sure there's a program out there that will automatically update DNS A records to point to your dynamic IP - problem is if that switches, it'll take the DNS system up to a day to filter throughout the net. This is why those services like No-IP are more expensive, basically they're more up to date but hosting a sub-DNS as it were. Your domain would point to them, and they would point to you.

Alternatively, VPS's or Shared Hosting plans are like $4 a month (Without a domain).